Dangerous Brains

September 13, 2004

Diet Extremism in the 21st Century
Part 1: Reexamining the Case for a Low-Carbohydrate Diet

Proponents of a high-protein, low-carbohydrate diet use the following general outline of human evolution and reasoning to support their claims:

2.5 Million Years Ago: Primitive humans begin to use stone tools and hunt small animals.
CLAIM: Until this time, our earliest primate ancestors consumed a diet much like modern chimpanzees. As a direct result of the increased nutrient-dense protein foods—i.e., small animals—our ancestral hominids’ brains begin to increase in size.

1.8 Million to 500,000 Years Ago: Homo habilis and Homo erectus evolve into Homo sapiens.
CLAIM: These three species have larger, more fully functional brains than their hominid ancestors and have the capacity to figure out how to hunt big game.

200,000 to 100,000 Years Ago: Neanderthal appears and is accompanied by modern humans. They cohabit the planet and eventually Neanderthal dies off. Fire and cooking are discovered.
CLAIM: For the next 190,000 years, humans continue as hunter-gatherers.

10,000 Years Ago: Modern humans begin farming out of necessity.
CLAIM: Through the advent of agriculture, man begins to cultivate grain, thus increasing his carbohydrate consumption. This 10,000-year period is insufficient time for modern humans to physiologically adapt to a high carbohydrate diet from grains, so the health of Homo sapiens begins to decline.

CONCLUSION: The best diet for humans is that of our Paleolithic ancestors—the diet on which we have evolved. This is proven by the fact that our Paleolithic ancestors were healthier than our more recent agricultural ancestors.

This nice, neat conclusion, unfortunately, doesn’t stand up well to close inspection, and its supporting claims are riddled with contradictions and inconsistencies.

For example, throughout these long stretches of time, various human species have evolved and disappeared. The “established dates” of the chronology given above are spurious, as such efforts at fixing dates for evolutionary epochs vary widely according to what and whom you read and when the material was published.

Experts vary so in their opinions and conclusions because information is constantly being updated and revised through new discoveries. There are numerous inconsistencies in fossil records. The result of this shifting picture is that all the foregoing conclusions and inferences remain little but unproven theories. Indeed, upon close examination, they raise more questions than answers.

How are we not physiologically evolved to handle high quantities of carbohydrates if our earliest ancestors, during their ape and chimpanzee stages, consumed them almost exclusively in the form of fruits and other plants for who knows how long?

If we are going to subscribe to the theory of cultural evolution, we are accepting the fact that our ancestors had to adapt to eating larger quantities of meat and fat long after already having established a physiology designed to handle large quantities of carbohydrates as a primary source of food. There is no reason to believe that large portions of these carbohydrate foods did not stay with evolving hominids all the way through the evolutionary process and right up to the present, as is evidenced in many modern hunter-gatherers.

Is it likely or even possible that once our so-called “earliest ancestors” got the taste for meat and fat, mostly in the form of small animals, they then simply gave up all the carbohydrates they had been consuming for untold generations?

There would be only one reason for any hominid to give up large quantities of a given type of food after having eaten it for hundreds of thousands of years, instead resorting to the exhausting and dangerous task of hunting big game: if the environment stopped producing it.

Why would the environment stop producing an abundance of plant foods? This might occur during long periods of consistently freezing weather. Ice ages (another theory) undoubtedly had a major impact on diet and health and represented long interruptions in our ancestors’ patterns of living. Arctic-type climatic conditions would have resulted in low carbon dioxide levels, thus contributing to less and smaller plant growth.

This scenario certainly would have encouraged phases of higher animal food consumption, leading many early hominids to hunt full-time. Temperate climate phases, on the other hand, would have brought an increase in plant and other easily gathered foods, similar to those in modern day hunter-gatherers’ diets.

Why did it take so long to create stone tools and go for the big game?

From 2.5 million years ago to 1.7 million years ago, our ancestors were still scavenging and eating small animals. Ancestral hominids finally reached the point where they could now use their larger brains to hunt big game. So says the theory. However, current findings have some paleoanthropologists now leaning toward the scavenger theory for Paleolithic humans as a means of obtaining the majority of their unpredictable sources of animal foods.

It is well known that most plant matter is scarce in the archeological record because it decomposes without a trace, unlike bones and pottery. If a variety of carbohydrates were available from the earliest times whenever the climate was suitable, it then stands to reason that they would have been available and consumed in large quantities continuously throughout the evolutionary process. It is always risky to compare modern hunter-gatherers to those of Paleolithic, Mesolithic, and Neolithic times because many of the food sources from those earlier periods are no longer available, and those that are have gone through various changes over the eras.

Does the big game diet fare any better in our nutritional history of brain advancement?

Concerning the increased consumption of meat and fat from small, easily obtained animals and its correlation to the increase in our ancestors’ brain size, this is a reasonable assessment, because nutrient-dense foods do nourish the brain.

However, what about the time it took brain size to develop? Did humans just sit around for nearly a million years, drooling and fantasizing about the large prey so abundantly available in their environment while consuming small animals and fruits, until they finally figured out how to put their large brain to some use so they could hunt the big game? Well then, so much for the attribution of brain development to nutrient-dense protein foods in the form of small animals. These foods may have contributed to brain size, but they obviously didn’t help much to promote brain function.

It is true that most varieties of game contain omega-3 fatty acids, zinc, L-carnitine, B12, and other vital nutrients utilized by the human body for brain function, strength, and immunity. Remember, we are assuming that our ancestors’ larger and more developed brains gave them the capacity to hunt, and that the consumption of larger quantities of nutrient-dense animal foods likely played a role in further brain development.


The second stage of advancement occurred around 1.7 million to 500,000 years ago when our hominid ancestors gathered their stone tools and took the risk of hunting big game.

Now, one must question whether they did this to supplement their existing diet of plants and small animals, or did they give all that up for the big stuff? It is still too early to tell how these slowly evolving big-game hunters are doing with their fully evolved brains as compared to their small-game-hunter ancestors, who took what seem to have been forever to get it together to hunt big game.

With the theory of slow, gradual ascension from apes to modern humans entrenched in our textbooks, it is no wonder that the image of the lumbering Paleolithic brute is so well established in people’s minds, even though most paleoanthropologists today are doing their best to change this conditioning. This is likely to remain a difficult challenge as long as the theory responsible for this image has not changed.

At this point, we have a hypothetical historical situation in which our earliest ancestors consume mostly fruits, insects, and occasionally small animals as a regular diet, much as apes and chimps do today. Then, according to theory, 2.2 to 2.5 million years ago a special line of hominids evolves. These new hominids have to learn to spot predators hiding in the tall grasses of the savanna in Africa. Since they no longer live in trees, they begin standing upright in order to see over the tall savanna grasses, and are the first species to become truly bipedal.

But hang on. Have you ever actually seen the tall grasses of the savanna? Even standing on someone’s shoulders and looking out over the tall grasses of the savanna, one would be hard pressed to spot a low-crouching, camouflaged lion. Anyone giving this idea even a little commonsense thought can see the absurdity of it.

Moreover, why didn’t any of the other monkeys, apes, and chimps evolve beyond their original status? Were they so frightened by crouching predators (and are they still today) they were able to ignore evolution and refuse to venture from the safety of the trees (and still do so today)?

The theory of human evolution is described in part as a primitive species going through processes of gradual change, through which this species eventually evolves into a more efficient and thus more advanced species. We start with nonhuman hominid ancestors whose diet consists of fruits, other plant parts, insects, and a greater quantity of small, easily hunted animals, which may eventually contribute to an increased brain size. Loss of body hair for ease in perspiring and other morphological changes also take place at some point.

These hominids evolve further and develop skills to hunt large game, which results in increased meat consumption. Isn’t this heavy game consumption really an example of adaptation to a food that was foreign, at least in large quantities, and apart from small animals? At this point, our hairless hominids are really eating the same diet they have been eating for millions of years, with the addition of greater quantities of large game.
What happens next?


Neanderthal and anatomically modern humans eventually appear out of the same evolutionary branch as Homo habilis and erectus. The appearance of both groups comes to fruition about 200,000 years ago (some say 100,000). As noted in the outline above, fire is discovered for cooking at about this time; indeed, the advent of cooked food may have been an additional influence on larger brain development.

Modern man and Neanderthal continue the patterns of big game hunting for around 100,000 more years. Neanderthals were robust and mighty hunters with fully developed brains; yet, whether by some trick of fate or simple ingenuity, it is we smaller-brained modern humans who survive and the Neanderthal who die out.

Now, I enjoy a nice barbecue with my friends and family on occasion. Still, one cannot deny that over the past several decades, we have been bombarded with scientific studies showing the dangerous, cancer-causing effects of grilled and charred foods, especially meats. I cannot help wondering how researchers can claim that our Paleolithic ancestors were so much healthier than later farmers. Isn’t this pretty much exactly how our big game, Paleo-hunter ancestors were cooking on a regular basis? After all, they had not yet learned to manufacture cooking pots: their food preparation had to be similar to modern grilling, only more intensely so due to their food being in direct contact with flame.

Direct flame is well known to cause high levels of free radicals in the blood of subjects consuming charred food. Most of the evidence found relating to food in prehistoric kitchen middens and other Paleo sites has been from charred remains. If this charred food represents the largest part of our ancestor’s diet, then antioxidant foods, such as fresh vegetables, could not have helped much to counter the effects of the toxic free radicals.

Either all the modern studies of the cancer-causing effects of charbroiled meats are way off the mark—or the healthy eating habits of our Paleo ancestors have been grossly misinterpreted.

Or perhaps both conclusions are circumstantial and dependent on other influences.
The 200,000-year-old discovery of fire use by early Homo sapiens fit nicely into the cultural evolution model—until a recent find in the northern Dead Sea valley (Associated Press, April 29, 2004). This new information places fire use at 790,000 years ago, throwing the evolutionary timeline wildly out of kilter.

At a campfire near an ancient lake in what is now Israel, researchers found evidence of meat consumption, including bones that had been broken to extract the marrow. Who these hominids were is unknown, but it is suggested they may have been a transitional form of Homo erectus, the precursor to Homo sapiens (modern humans).

Does this report mean that cultural development could have occurred 590,000 years sooner than we thought? If so, we could be facing a significant modification in our cultural evolution theory. Or do scientists need to recalculate the arrival of Homo sapiens? At any rate, the effort to reconcile this new timeline for fire use with the accepted orthodox timeline boggles the mind.

There’s more. Orthodox theory implies that we are “just surviving” for 120,000 years, often threatened by a harsh environment and forced to hunt large game. Recall that Neanderthals are robust, great hunters who possess larger brains than we have today, as do Cro-Magnon, our relatives. Yet, both go extinct. This apparent contradiction may be partly explained by the evidence of the worldwide practice of cannibalism, a taboo subject with the low-carbohydrate-diet enthusiasts. Perhaps the physical taming of fire has little to do with taming the spiritual fire, which while hard to quantify is equally necessary for civilization.

If we consider only the smaller-brained Homo sapiens and evaluate our progress for the last 200,000 (or is it 790,000?) years, we reach the mathematical conclusion that it takes us at least 190,000 years of hunting big game before we figure out that we can domesticate animals for food instead of chasing them down and competing with dangerous predators.

This means we are still foraging, hunting, gathering, scavenging, caving, and roaming right up until around 10,000 years ago. (So much for the thousands of years of including large game into our diet and the effect it supposedly had on the development of our brain.)


Suddenly, as if out of nowhere, Homo sapiens begins agriculture in several parts of the world at once. Whole grain is cultivated and added to already existing nutrient-dense protein food sources; human brain development leaps to unprecedented heights.

We continue hunting to supplement our domesticated plant and animal food sources. Furthermore, we move out of the caves, start making clothes from plant fibers, build monuments, and begin learning astronomy, geometry, and other sciences. With this new dietary addition of cereal grains, we become fully civilized in a very short time. Yet before this, when on hunter-gatherer diets, Homo sapiens progresses very little even over the course of hundreds of thousands of years.

Perhaps grain and plant cultivation combined with animal husbandry is cause enough for this giant step in human progress and brain development. Could this extraordinary development have been the first and only such dramatic shift in humanity that occurred since our sojourn out of Africa? Stone tool development, hunting, the discovery of fire, some ritualistic burials, and cave artwork are explained easily enough through orthodox theory. Many of these developments are said to have occurred within the last 40,000 years. However, Homo sapiens’ leap to agriculture and civilization is not as easily explained.

For almost 200,000 years, our ancestry makes few basic changes, but 10,000 years ago, we suddenly make extraordinary changes with the advent of agriculture, which carries us to the present era, in which we have already been to the moon and are on our way to Mars.

Is it true that our relatively large-brained Paleolithic human predecessors could not have thought of smelting copper or other metals? Did they not have the desire enough and the one inventive mind among them to build a flying glider, even out of simple wood-and-tar materials? And is it true they did not build any cities for 190,000-plus years?

Is the story of prehistoric humankind really nothing but a grim struggle for survival?
The expert might respond, “Well, we haven’t found any evidence to indicate anything other than what orthodox theory suggests.” My response is, “That is not true. Keep looking—because what we do know at this time is limited to the knowledge of a few ancient historians and a couple of hundred years of excavations and scientific research, much of which is filtered to fit the prevailing theory. More information is being discovered almost daily.”

Personally, I have not given up on our ancestors, the ones who gave us the knowledge to go beyond the basic need to survive and to explore our universe. Rather than being forced into agriculture about 10,000 years ago, as some historians hypothesize, many early Homo sapiens most likely begin the practice of agriculture many thousands of years earlier. Having had to abandon these practices, many were later forced to live in caves and subsist on mostly game, fish, and other wild animals because of extreme climatic changes due to catastrophic events as indicated in traditional legends throughout the world.


Some adherents of low carbohydrate diets suggest we should eat like our Paleolithic ancestors. But what exactly does that mean? Which ones should we be eating like—the ones who ate more plant foods or the ones who ate more animal foods, the humans or the other hominids? How about our cannibal ancestors? Our Paleolithic ancestors’ diets varied as greatly as do those of today’s traditional hunter-gatherers around the world.

Most of today’s low carbohydrate diets lean toward the high protein group and some suggest little to no carbohydrates; others permit tubers, fruits, and honey. For Paleo-diet advocates, grains are usually discouraged, especially wheat, barley, and other gluten-containing grains. There are numerous problems with this extremist thinking. There is no doubt that protein and fats are necessary for proper metabolic balance and general good health, but so are highly nourishing carbohydrates in the form of cereal grains.

Paleo diet advocates often cite the Egyptians as an example of why one should not eat grains. Some Egyptians statues have bloated faces and waistlines, and fossil evidence of some Egyptians reveals low bone density. These and other problems are often cited as caused by a high carb (grain) diet. While this is true to some degree, any Egyptologist knows that in its long history, this extraordinary culture experienced widely varying periods of abundance and scarcity. The Nile, their primary source of water, was susceptible to extreme flooding at times; drought was also experienced periodically, sometimes lasting for generations. During times of abundance, Egypt’s culture thrived, with a wide variety of health sustaining foods. Cattle, vegetables, grain, fowl and many other foods were essential components of their diet. In difficult eras, the culture suffered and had to make due with stores of grain and other foods that could be preserved.

Archeologists have found an essentially similar pattern of extremes in every ancient civilization; therefore, to state that all Egyptians throughout history were weaker and less healthy than Paleo hunter-gatherers because of a high grain diet is absurd and doesn’t take into consideration the many other important factors and changes in Egyptian history. Paleo hunter-gatherers were not exempt from such extreme dietary deficiencies either (as is evidenced, for example, in periods where cannibalism was prominent) as is common in modern day hunter-gatherers.

However, the negative attitude toward carbohydrate consumption has little to do with whole grain consumption; it is rather based on the imbalances caused by highly refined and denatured products derived from poor quality, refined grain products and the large consumption of pharmaceuticals. We should face this problem not by eliminating carbohydrates, which are necessary for good health, but by replacing our modern, refined versions with naturally grown complex carbohydrates, such as those that have been consumed in cereal grains by traditional agriculturalists around the world for at least 23,000 years.


A balanced traditional diet consisting of a wide variety of quality fruit, vegetables, grains, legumes, nuts, seeds, and animal protein supplies the widest spectrum of nutrients, well beyond what any modern fad diet can claim. The most extraordinary thing about this is that hardly anyone in the modern world has experienced this type of traditional diet for at least two generations! Instead, we have been overwhelmingly consuming a diet of highly refined carbohydrate foods accompanied by processed, factory farmed animal protein, toxic trans-fats, and loads of pharmaceuticals. Any close evaluation of these modern food sources reveals the truth about why health is on the decline and obesity is on the rise—as well as why there are so many extreme dietary trends.

We are living in the age of designer diets. There are diets for every ill and every belief. I have yet to meet one person on a designer diet who, before commencing that new diet, had eaten a high quality, balanced diet of traditional foods.

It is natural to some extent that such designer diets appeal to us: we seek release and relief from the debilitating effects of processed foods that we have been manufacturing and consuming for over the last century or so. Sometimes the appeal of a particular designer diet lies in the fact that we are trying to escape from (or to compensate for the effects of) some other designer diet that didn’t fulfill our desire for weight loss, more vitality, or some other health goal.

Much of the food consumed by most people today consists of processed, denatured foods, laden with preservatives and many other nonessential substances that do little to support health and much to detract from it. More and more people are realizing this, so they naturally seek ways to remedy the problem and reestablish their health.

Enter designer diets: lots of them, and all different too—yet all of them offer similar promises. Those that stress natural unprocessed, and preservative-free foods help us to gain insight on the importance of quality in our diet. These are the only ones worth considering if we truly want to be certain what we are eating is healthy. However, even among these more naturally oriented approaches to diet, the balance of nutrients often remains a very important consideration.

The first category of people seeking designer diets are those needing to escape from nutrient-deficient foods for whatever reasons, health, weight loss, etc. The second category of people seeking designer diets are those who have already tried at least one new, restrictive diet and failed.

Those of this second category try another designer diet, sometimes continuing the new diet for years, or perhaps only months. All eventually find the need to eat things not on the diet—some often, others only occasionally. This is natural: designer diets tend to restrict the very foods with which we are most familiar, and in eliminating them from our diets, we often feel deprived.

Another reason for distractions from a diet is a lack of energy due to a lack of balanced nutrition; increased use of stimulants is a common response, but sometimes these stimulants (coffee, tea, tobacco, etc.) can come to comprise a larger percentage of our diet than healthy foods. Actually, coffee, chocolate and other stimulants are good barometers for determining how well one’s diet is working: the more of them one consumes, the less effective the diet. The need for these foods, other than in moderation, is a strong message that suggests changes in one’s diet are called for.

In general, modern Homo sapiens are unsatisfied nutritionally and, thus, metabolically. This is not the result of a simple-minded generalized notion of “carbohydrate overload.” Nor is it caused by the consumption of traditional whole grains in the diet, often mistakenly classified by low carb proponents as being in the category of “bad carbs.” Quality whole grains are health-promoting foods when balanced with adequate amounts of protein, fats, and fresh vegetables.

Organic, complex carbohydrates and processed, junk-food carbohydrates are as different from one another as a chicken is to an apple. If there is a beneficial aspect of a low carbohydrate diet, it is in the concomitant suggestion by many teachers to reduce or eliminate junk-food carbohydrates. Once such a shift is accomplished and protein and fat are increased, one’s metabolism gets a jump-start from years of stagnation caused by excessive, poor quality carbs. One is then energized, tends to lose weight and experiences life differently, at least for a while. So there may be a temporary benefit in a low carbohydrate diet—but beyond that temporary benefit, it is critically important to make a distinction between the qualities of different carbohydrates and to eat a variety of health-promoting foods, including grains and legumes.


All nutritionally related health problems invariably result from a combination of factors. Some think obesity, for example, is caused simply by excessive fat consumption, but it is the quality of fats and the imbalance between healthy fats, proteins, and carbohydrates that principally contribute to extreme weight retention. Refined carbohydrates also contribute to obesity, often even more than fats. All essential macronutrients play a role in every diet-related illness; it is never just one thing.

Try removing one category of nutrition from your diet; inevitably, you will find yourself eating it again in some form or other. After more than 25 years in the natural health field, I have had the opportunity to hear many stories and witness many dietary tragedies. Here is a common statement I hear from those trying to adhere to a low carbohydrate diet: “When I was doing it I felt great!” This sort of past-tense expression is typical with designer diets that depend on restrictions or limited choices. Deprivation of a variety of healthy foods makes these types of diets difficult to maintain. Another frequently heard statement is, “I really enjoy the food, but I find myself cheating a lot.” Again, depriving oneself of a variety of healthy foods eventually leads to compulsive overeating and other emotional problems.

Those with allergies to grain (wheat and gluten-containing products) should naturally avoid gluten-containing grains—if they do indeed produce an allergic reaction. I say “if” because there are people who are gluten-intolerant who can still eat high quality grains traditionally prepared by fermentation, soaking, or sprouting. Also, for people experiencing this problem it is important to consider that the problem itself was not caused by high quality traditionally prepared grain as part of a balanced healthy diet. Gluten intolerance problems can be carried from generation to generation and are exacerbated and caused in part by refined-gluten-containing products. However, many of the symptoms of gluten intolerance (leaky gut, allergies etc) are duplicated in those with a history of immune-suppressing substances, especially pharmaceuticals, drugs and chemicals of all kinds. Indeed, the actual causes of these health problems may lie more in these products than in any others.

It is interesting to note how saturated fats of all types have been accused for years of causing a host of problems, from heart disease to cancer, yet today; traditional saturated fats are finally starting to be recognized as healthy and essential macronutrients. As it turns out, the problems once believed to be caused by these traditional fats were in fact caused by trans fats and refined polyunsaturated oils.

Protein, too, has been demonized in the past; now it appears to be carbohydrates’ turn to take the stand and be accused of the majority of the Western world’s health woes.

In order to prevent future problems, we must be careful not to make the same mistake we made with fats: that is, we need to avoid the simplistic error of classifying all carbohydrates in the same category. Certainly it is important to acknowledge the problem of gluten intolerance for some people, yet it is at least as important to consider the long history of grain consumption among healthy peoples eating a balanced traditional diet.


With quality carbohydrates, very few people have had “too much of a good thing.” In other words, not many people have overdosed on unrefined, complex carbohydrates; most have their excessive carbohydrate experience by way of refined sugar and refined grain products.

However, there are still those scant few who believe they have developed problems from the excessive consumption of good quality grains they had consumed for a number of years. While it may be true that grains were consumed in excess, grains cannot be accused of causing these people’s difficulties. In my observation, these health problems develop from a diet lacking an adequate balance of protein, fats, and other nutrients needed to balance complex carbohydrates.

There are many designer diets that promote high quality natural carbohydrates yet discourage the intake of high quality fats and proteins, often favoring incomplete protein sources or “natural” junk foods, such as those derived from nontraditional soy products that have no health benefits. Consuming even high quality carbohydrates, such as organic whole grains, without sufficient quality protein and fats can be an example of when too much of a good thing goes bad.

Indeed, this can happen all too easily with any nutritional source, be it carbs, proteins, or fats. Unbalanced high natural carbohydrate diets are no more beneficial to our health than unbalanced low carbohydrate diets. When people eat a healthy diet with a variety of healthy foods in a balanced way, they have little need for designer diets.

This does not mean you will not need to adjust your diet on occasion to accommodate life’s changes. However, when you have all the finest quality tools at your disposal, you are more apt to successfully work out life’s often complex health issues than if you have only a few good tools at your disposal and are unaware of what needed elements you’re missing. With all the proper nutrients available and utilized, weight problems, energy loss, and similar concerns are easily remedied, and you become satisfied on many levels of your being.

In other words, it is easier to address diet-related problems by starting from a balanced traditional diet than it is to start with an extreme diet that will lead, sooner than later, to other extremes.

To be continued

The above material is excerpted from the forthcoming and newly revised book by Steve Gagné, The Energetics of Food

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